Tumours
Benign Tumour - Does not affect the surrounding tissue, simply takes up space. These are non cancerous. |
Malignant Tumour - Spreads into, or invades nearby tissues and can travel to distant places in the body to form new tumours. (Metastasis) |
Cell Differentiation
As organisms grow, they need specialized cells to preform certain life functions. |
Cell differentiation refers to the stage of developement where specialized cells are formed. |
All cells in the body are made through Mitosis and they start off as identical cells called stem cells |
Each stem cell has the ability to become a specialized cell. |
Organs
Organ: A part of the body that is made up of cells and tissues that preform a specific function. |
Stem Cells
Stem cells can be harvested from an umbilical cord or placenta after birth. |
Larger amounts of stem cells can be obtained from unused fertilized embreyo. |
Stem cells can be used to repair damaged tissue or organs. |
Digestive system
The digestive system is an organ system that takes in food, digests it, and excretes the remaining waste. It is made up of the digestive track & accessory organs. |
Digestive track
Stomach, - Mouth, esophagus, small intestines, large intestine, anus |
The entire track is lined with epithelial tissue, and goblet cells are present. (They secrete mucus) |
Functions of the mucus: Protects digestive track from digestive enzymes and allows the material to pass smoothly along. |
3. Stomach
The stomach is a major organ in the digestive system. |
Its main function is to hold & churn food to continue digestion. The stomach lining contains cells that produce digestive enzymes & acids. |
The stomach is supplied with nerves that signal when we have had enough to eat. |
The Circulatory System
The circulatory system’s main function is to transport substances throughout the body. |
It moves nutrients from the intestines to the body’s cell. |
Blood flows through the lungs to pick up oxygen and delivers it to cells. |
Blood Vessels
3 Types of blood vessels: |
Arteries: Carry oxygenated blood away from the heart. |
Veins: Carry oxygen-poor blood towards the heart. |
Capillaries: Tiny blood vessels that connect veins & arteries. They have thin walls to allow substances to diffuse between blood and surrounding tissues. Oxygen & nutrients diffuse from blood into tissue, carbon dioxide & waste pass from tissues into blood to be disposed of. |
Gas Exchange
• Capillary walls are thin |
• Oxygen diffuses through capillaries in alveoli into blood. |
• Carbon dioxide in bloodstream diffuses into alveoli |
Role of a Leaf
Photosynthesis occurs in leaves. |
Light + H2O + CO2 → C6H12O6 + O2 |
Two types of vascular tissue
Xylem:
Elongated cells that transport water & minerals up from the roots |
Phloem: Transport sugars throughout the plant |
Tissues in Plants
Dermal Tissue → Covers outer surface of plant. |
Vascular Tissue → Conducts materials within plant. |
Ground Tissue → All tissue other than dermal or vascular. |
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Metastasis
Metastasis - The developpement of secondary malignant tumours at a distance from an original tumour. Cells from the original tumour break through blood vessel walls to travel to other areas of the body. |
Causes
- DNA mutation |
- Cell avoids apoptosis (the process of programmed cell death) |
- Hereditary |
- Environmentally triggered: Carcinogens (Environmental factors that cause cancer such as radiation, chemicals, and tobacco) |
Levels of organization
Multicellular organisms are made of many types of cells. |
Each cell is specialized; specialized cells cannot survive on their own. |
Cells work together as a part of a larger group of cells that collectively make up an organism. |
Specialized Cells
Cells specialize by producing different proteins. |
Even though all the cells have the same genes in their DNA, not all the genes are ‘turned on’, allowing the cells to be different. |
1. Mouth
The mouth begins the process of breaking down food. |
It breaks down food in 2 ways: mechanically (using teeth and tongue) and chemically (using enzymes to break apart carb molecules) |
Once the food is broken up & softened with saliva, it is swallowed and passed to the esophagus. |
4. Intestines
The intestine connects the stomach to the anus. the intestine lining has cells thats produce mucus & contains many blood vessels. |
Small Intestine
About 6 m long & narrow
Nutrients diffuse through the intestinal wall & into the bloodstream |
Large Intestine
About 1.5 m Long
Lining absorbs water from indigestable food. |
Parts of the Circulatory System
Blood- Blood is a type of connective tissue that circulates throughout the body. |
The Heart- Pumps oxygen rich blood to the body & pumps oxygen poor blood to the lungs for oxygenation. |
Blood Vessels- The blood vessels form a network throughout the body to transport blood. |
The Respiratory System
The respiratory system provides oxygen for the body and removes carbon dioxide through a process called gas exchange. |
Respiratory System
Nose & mouth: Openings to body. They warm, moisten, and filter air. |
Pharynx: Throat - pathway for air to travel to tranchea. |
Trachea: Wind pipe - pathway for air to travel to lungs |
Bronchi: Two tubes that branch off from the trachea. They deliver air to lungs. |
Bronchioles: Responsible for gas exchange inside alveoli |
Alveoli: Small air sacs at the end of bronchioles; responsible for gas exchange. |
Lungs: Two ballon like structures, they release CO2 and take in O2 |
Diaphragm: Large sheet of muscle that moves up and down to aid in breathing. |
Spongy Mesophyll Layer
Loosely packed cells |
Large air spaces between cells allow for gas exchange during photosynthesis. |
Palisade Layer
Major site of photosynthesis |
Cells are tall and packed closely together |
Cells help capture as much light as possible. |
Lower Epidermis
Contains stomata |
Stomata: Pores surrounded by guard cells which regulate its opening. |
Stomata open during the day and close at night. |
Upper Epidermis
Contains cuticle |
Cuticle: waxy noncellular top coat of leaf that prevents water loss and controls gas exchange. |
Plant Cell Differentiation
Plant cells undergo cell differentiation to become specialized. |
Cells that are not specialized are called meristematic cells. |
They are found at the tip of the plant. |
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Diagnosing Cancer
Imaging tests: Create pictures of the inside of the patient's body. They help doctors detect tumors or abnormalities that could be cancer. |
Biopsy: A small sample of tissue is taken from a suspicious area and examined under a microscope to check for cancer cells. |
Laboratory Tests: Urine and blood tests help doctors identify abnormalities that can be caused by cancer. |
Cancer Treatements
Chemotherapy: Using powerful drugs to destroy cancer cells or stop their growth |
Radiation therapy: Using high-energy rays to target and kill cancer cells. |
Surgery: Removing the tumour of affected tissue from the body. |
Tissues
Tissue - Collection of similar cells that preform a function |
4 Major types of tissue: Epithelial, Connective, Muscle, Nerve. |
Nerve Tissue
Long, thin cells with fine branches at the ends capable of conducting electrical impulses. |
Function: Sensory, communication in the body, coordination of body functions. |
Muscle Tissue
Bundles of long cells called muscle fibres that contain specialized cells capable of shortening or contracting. |
Function: Movement. |
Epithelial Tissue
Thin sheet of tightly packed cells covering surfaces and internal organs. |
Function: Protection from dehydration and creates low friction surface. |
Connective Tissue
Various cells and fibres held together by a liquid, solid, or gel matrix. |
Function: Support and insulation |
2. Esophagus
The esophagus is a muscular tube that connects the mouth to the stomach. |
It is made of smooth muscle tissue, which can contract and relax without conscious thought. This movement is controlled by nerve tissue. |
Accessory Organs
The liver, pancreas, & gallbladder assist in digestion by supplying digestive enzymes. |
The liver produces bile, a fluid that helps break down fats in food. |
The pancreas produces insulin, an enzyme that regulates blood glucose levels. |
The gallbladder stores the bile that the liver produces. |
Blood
Blood has 4 components: |
Red blood cells: Make up almost half of the blood’s volume and contain hemoglobin which gives the cells a red colour and allows them to transport oxygen. |
White blood cells: Make up less than 1% of blood’s volume. They recognize & destroy bacteria and viruses. |
Platelets: Make up less than 1% of the blood. They help with blood clotting. |
Plasma: Makes up over half of the blood’s volume. It is a protein-rich liquid that carries the blood cells. |
Plant Functions
• Exchange gases with their surroundings |
• Transport water and nutrients around within their bodies |
• Reproduce |
Hierarchy of Plant Body
Plant body is divided into two parts; roots & shoot systems |
The root system is made up of roots |
The root system is responsible for anchoring the plant and absorbing water & minerals from soil and to store them. |
Shoot System
Stem → Supports, transports material, stores food, protects. |
Leaf → Supports, protects, is the site of photosynthesis, and reproduction. |
Flower → Responsible for sexual reproduction, and stores food. |
Plant Growth
Apical Meristems: Tips of plant roots & shoots - allow plants to grow longer and develop specialized tissues. |
Lateral Meristems: (side to side) Under bark in stems and roots of woody plants. Allows plants to grow wider and develop specialized tissues. |
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